The progress of Information Technology and the development of computer systems has allowed the creation of very large knowledge bases containing thousands of documents and electronic files. Computers are used for collecting, storing, sorting and quickly retrieving references to documents contained within such repositories. The exploitation of such repositories has commonly been based on the use of indexing techniques that allow keyword-based searches for the retrieval of the documents upon request. By formulating a query based on a given set of keywords, a search engine generally provides a ranked output list of documents.
IR techniques have been employed in a wide variety of situations where a user needs precise and quick access to reference documents. One example of such a situation is helpdesk or hotline services which are organised for providing quick and effective technical support to customers of computer and other products. Indeed, the daily work of help-desk analysts providing such services is often supported by sophisticated IT systems containing tens of thousands of problem solving documents for all aspects of the products concerned. Upon a problem being raised by a customer, a helpdesk analyst has to examine the problem and provide a quick solution meeting the particular concern of the customer. To achieve this, the helpdesk analyst often abstracts the problem into a few keywords. However, IR techniques based on keyword searches usually return, by far, too many documents and only a few of the listed documents turn out to be of any real use to the helpdesk analysts—a factor that inevitably jeopardises the effectiveness of the services which are rendered to the customer. In most cases, first line agents of the helpdesk services have very little time for finding an effective and practical solution to a single customer's problem, and the use of the traditional techniques based on keyword searches provides too much noise and returns too many documents to be easily exploited by the first level helpdesk staff.
Moreover, the handling of the references and documents that are retrieved by keyword-based search techniques requires professional skill and wide experience from the technicians in order to recognise, among the number of references being cited, a particular document which could be useful for solving the customer's problem. The need for such experience and professional skill is a further difficulty for the development of help-desk services which are notorious for being subject to a large turn-over of staff.
Therefore, it can be seen that in the area of helpdesk services, there is a particular need for improving searching techniques in order to enhance the relevance of the documents and references which are retrieved from a document repository.
However, whilst the techniques to be described below are particularly suited to this area, they nevertheless address the general problem of improving the access to a collection of documents or other resources which are stored within a database. Therefore application of the techniques in other areas is not excluded.